This invention relates to a universal drive or power module for providing shaft power input to any one of a plurality of different special purpose woodworking tools.
Applicants' assignee, Shopsmith, Inc., has for a number of years, offered a variety of special purpose woodworking tools. Such special purpose tools have been specifically designed for use with the "Mark V" multi-purpose woodworking tool made in accordance with the teachings of U.S. Pat. No. 2,927,612 issued Mar. 8, 1960 to Edgemond, Jr., et al.
The multi-purpose "Mark V" tool as disclosed in the above-identified patent of Edgemond, Jr., et al, itself provides a variety of woodworking capabilities for the serious hobbyist, including table sawing, vertical drilling, horizontal boring, and lathe turning, among other capabilities. In order to expand the use of the basic multi-purpose machine, and to provide a wider range of woodworking capabilities, a series of special purpose woodworking tools has been developed for attachment on and use with the multi-purpose tool. For this purpose the multi-purpose tool was provided with a pair of laterally spaced auxiliary mounting sockets. These sockets were proportioned to receive the laterally spaced eccentric mounting posts of special purpose tools. The headstock was further provided with a pair of auxiliary output drive shafts or hubs for the coupling to the input shafts of such special purpose tools.
The auxiliary drive shafts, defined respectively by reference numerals 164 and 107 in patent '612, were vertically spaced with respect to the elevation of the pair of tube-receiving sockets, and provided the designers of the special purpose tools with a selection of available power inputs at two specific elevational locations. As a result, any given special purpose tool has a power input shaft connection at one or the other of two elevational positions for coupling with one of the multi-purpose power drive shafts, through an intermediate removable shaft connector or coupler.
The special purpose woodworking tools which have been specially designed and developed for use as an adjunct to the multi-purpose woodworking tool shown in patent '612 include, among others, a belt sander as shown in U.S. Pat. No. 2,857,717 issued Oct. 28, 1958, a jointer as represented by the reference number 47 in patent '612, and as further described in Bulletin No. 505681-B of Shopsmith, Inc., a scroll saw as described and claimed in the copening application of Legler et al, Ser. No. 226,172 filed July 29, 1988, a jig saw as described in Bulletin No. 505644, a band saw as described in Bulletin No. 505641, and a belt sander as described in Bulletin No. 505642, all published by Shopsmith, Inc.
Each of these special purpose tools is supported on a pair of depending, laterally spaced-apart mounting posts. The posts are adapted to be received within the postreceiving auxiliary sockets positioned at one end of the multi-purpose woodworking machine.
The depending posts are generally formed with eccentric offsets which permit the respective special purpose tool to be laterally adjusted with respect to the axis of one the output power shafts of the headstock, and then locked in adjusted position.
Since many of the above-defined special purpose tools are, themselves, primary woodworking devices, and since the multi-purpose woodworking machine for which such auxiliary devices have been designed is not otherwise available for its primary functions while it is being used to support and power one of the special purpose tools, a need has arisen for a universal power module which will support and provide variable speed drive power to each of such tools in accordance with its specific requirements. Desirably, such power module should also have an auxiliary output shaft for supporting simple rotary buffers, sanding drums, and the like, for use by the hobbyist apart from or in addition to the principal multi-purpose woodworking machine.
A need also exists for such a universal power module which is both simple and reliable in construction, one which can be manufactured at relatively modest cost, and which inherently provides the necessary mounting precision required for utilization of the full potential of the line of special purpose tools, as described above.